Coupling of superconductors through a half-metallic ferromagnet : evidence for a long-range proximity effect

Abstract

Here we examine the ferromagnetic/superconducting proximity effect in half-metallic ferromagnetic La_(0.7)Ca_(0.3)MnO_(3) and high-T_(c) superconducting YBa_(2)Cu_(3)O_(7) artificial structures. We have found experimental evidence for the coupling between superconducting layers through ferromagnetic spacers in superlattices. This is consistent with a long-range proximity effect in half-metal ferromagnet/d-wave superconductor structures.